A group of pediatricians have found children prescribed antibiotics for respiratory infections have an overall increase in their frequency of return office visits. The pediatricians performed the study after their concern for the overprescribing of antibiotics in child respiratory infections. According to lead researcher, Dr. Michael Pichichero, while some doctors prescribe antibiotics for nearly all patients with respiratory infections, "there is, however, no scientific rationale for such antibiotic use." This is because most respiratory infections are caused by viruses and antibiotics work only against bacteria.